7gb trans screens 2 where r the
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=70967
Printed Date: 28 Jun 2025 at 11:51am
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Topic: 7gb trans screens 2 where r the
Posted By: edwin
Subject: 7gb trans screens 2 where r the
Date Posted: 27 May 2013 at 7:46pm
does anyone have a 7gb . and had trans problems ..like some times it will move sometimes it wont..hydraulic flow chart shows 2 screens is this correct?any help wouid be appreciated. thanks. 
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Replies:
Posted By: Dozer
Date Posted: 28 May 2013 at 5:45am
| My HD7G has the same problem. It looses trans pressure when it warms up and stops moving. I have done everything short of pulling the transmission without success. The transmission has clutch packs like all automatic transmissions. When you loose hydraulic pressure because of leaks it will not move. You should check for external leaks and blockages including hoses that might be leaking or sucking air. If this does not help, pull the transmission and check the clutches. My HD7G is for sale as a project. If there are no takers I will sell parts. When the HD7G was working I really liked it, but now I use my HD6G's because the less complex HD6 is reliable. |
Posted By: gemdozer
Date Posted: 28 May 2013 at 5:37pm
| Yes your trans. have 2 streaners and after cleaning them and she do't working better check your transmission pump pression |
Posted By: doctorcorey
Date Posted: 10 Jun 2013 at 11:03am
| I have a trans pump for this model for sale. 24385 I believe. |
Posted By: doctorcorey
Date Posted: 10 Jun 2013 at 11:31am
| Yes, two filters. One is visible as a cannister above the trans. The other is a combination on the lower FRONT of the trans case. It strains the tranny pump inlet and the steering pump inlet. Sometimes if the combination screen is really clogged, you may get erratic steering clutch action as well as trans slippage. What are your pressure readings on the trans clutch and trans main pressure at high idle? |
Posted By: doctorcorey
Date Posted: 10 Jun 2013 at 11:32am
Posted By: doctorcorey
Date Posted: 10 Jun 2013 at 11:35am
| I want to elaborate on my last post. Since the two pumps (as described above) use the same screen, the pump with the stronger inlet signal may "steal" the available fluid from the other pump due to filter clogging and associated reduced available flow volume,causing erratic action of one or both pumps. |
Posted By: AusHD6
Date Posted: 10 Jun 2013 at 4:47pm
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2 weeks ago my HD6EP started showing the same symptoms as Edwin and Dozer described on theirs. Hot or cold the thing would erratically loose tranny and clutch pressure,(kind of like a pump was loosing prime), when the pressure dropped it wouldn't pick up a gear and if it did pick up a gear it wouldn't push (tranny clutches slipping). When the pressure was good all was good.
I dropped the oil out when hot and replaced the 3 paper filters (two for steering and one for tranny mounted on a bracket at the front of the tranny) I checked the scavenge pump steel suction screen at the bottom right of the tranny and also the small screen on the small torque converter bleed back line (Pre S/n 18765? 1965) and both were clean. I filled it back up with oil but the problem was still there??????
In the schematic in the service manual it showed a suction screen for the tranny/convertor/steering pumps but nothing was shown in the owners or parts manual???? Later I found a picture of it in the steering clutch section of the parts manual.
I spoke to Ac_sd and MervHD6 and they told me that the suction screen that I hadn't checked is inside a casting at the left front of the tranny under the paper filter. It's bolted on with 4 bolts and has two suction hoses coming out of it. When you pull the casting out you will see the large pleated steel screen screws into the back of it --- man was it clogged up. It fits into a cavity on the left side of the tranny but draws oil from the crown wheel housing. I spent 20 minutes cleaning the crap out of the screen with petrol and compressed air then put it all back together. It now goes like AC intended!!
Thanks Bob and Merv
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Posted By: edwin
Date Posted: 10 Jun 2013 at 10:37pm
| Hey everyone,thanks for all the info. really appreciate it..I have cleaned the big screen on left front side of tranny and small 1 on bottom right hand side.I hear a buzzing noise like a pump if starving for oil. It does not make any sense to me .The pump on the top back of torque con. Has a line that goes from small screen lower right hand side topump then to left side final drive housing.If anyone would like to talk about it on phone. I would appreciate it. pc just take to long.I Thanks 417-718-0766..lebanon mo.. |